Flexible polyvinyl chloride (PVC) suction hoses having outside diameters formed with a spiral helix and a smooth inner bore are widely used, for example, in the fire industry, for trash pumps, in construction mining, for solid material transfer and liquid manure pumping. These flexible PVC hoses typically have outside diameters between 11/2" to 6" and because of their non-uniform, spiraled helix shape, are difficult to seal and connect to a source of pressure such as a fire hydrant.
Typically, to connect the hose to a fire hydrant, a connector having a first end with a barbed shank is inserted within the smooth inner bore of the hose. A second end of the connector extends outward from the hose for coupling to the fire hydrant.
To seal the hose to the barbed shank, a pair of metal (e.g. aluminum) hose collars surround the hose and are generally coextensive with the barbed shank. The hose collars are tightened together and compress the hose onto the barbed shank. In this manner, a seal is formed between the hose and the connector wherein the hose collar prevents the movement of the hose relative to the connector.
The difficulties encountered with currently available hose collars formed from aluminum are numerous. One difficulty is that leaks occur between the hose and barbed shank because the hose is frequently "pinched" when the hose collars compress the hose. Pinching causes air to be sucked into the hose during drafting causing pump cavitation and loss of prime. Pinching occurs because the hose collars have an inside diameter less than or equal to the outside diameter of the hose so that as the hose is compressed by the hose collars, a portion of the hose is deformed into an area between the parting faces of the hose collars, thus causing a leak. Variations in the outside diameter of the hose can exacerbate this problem.
Another difficulty is that current aluminum hose collars require parts made from two separate castings. These castings are rigid and provide no means of flexing to allow for proper fit, resulting in pinching between the parting faces. The leakage caused by the pinching prevents the ability to draft.
When not in use, hose collar assemblies are frequently mounted on hose trays. As depicted in FIG. 6A, current aluminum hose assemblies hang off the hose tray and are subject to damaging the hose due to excessive bending and chafing of the hose collar assembly.